Dr. Sim is also co-founder of Vivli, the world's largest data sharing platform for participant-level clinical trial data. In 2005, she was the founding Project Coordinator of the World Health Organization's International Clinical Trials Registry Platform, where she led the establishment of the first global policy on clinical trial registration.

Dr. Sim has served on multiple advisory committees on health information infrastructure for clinical care and research, including committees of the National Research Council and National Academy of Medicine. She is a recipient of the United States Presidential Early Career Award for Scientists and Engineers (PECASE), a Fellow of the American College of Medical Informatics, and a member of the American Society for Clinical Investigation.